BBC diplomatic correspondent Barnaby Mason answers key questions about the proposed Middle East peace conference, assessing whether it could be convened and the roles of the main parties.

What is the peace conference proposal?

Israeli Prime Minister Ariel Sharon has proposed a regional Middle East conference to be chaired by the United States. He says the idea is acceptable to Washington. The State Department confirms it is being considered but says more discussion is needed to see how it might be done.

The assumption is that Mr Sharon would agree to almost any Palestinians except him. The whole thrust of Israel's military offensive in the West Bank has been to weaken and humiliate Mr Arafat, though his standing in Palestinian eyes has risen.

Why does Sharon want to exclude Arafat?

Mr Sharon's loathing of the Palestinian leader goes back many years. He has publicly regretted that Israel did not kill him 20 years ago in Beirut.

Mr Sharon and Mr Arafat each regards the other as a terrorist. Mr Sharon also seems to believe that if he refuses to talk to Mr Arafat, other Palestinian leaders will emerge. This seems wishful thinking.

It is also fanciful to suppose that other Arab leaders would agree to attend a regional peace conference if Yasser Arafat were excluded.

And what is Mr Arafat's attitude?

Assuming it is relevant, Mr Arafat says he is ready for an immediate regional conference, provided there is an immediate Israeli withdrawal from Palestinian towns.

Are there any other objections to the idea?

Syria and Lebanon are not on Mr Sharon's list of invitees. They are two of the most important parties and there will be no overall peace settlement between Israel and the Arabs until there is a deal with Syria and Lebanon as well as with the Palestinians.

What could a regional peace conference talk about?

That is the key point, and it is hard to tell. The idea has been been tried before. The Madrid conference of 1991 brought Israel and the key Arab parties together for the first time and launched the process that led to the interim agreements on Palestinian autonomy.

But many believe Mr Sharon is intent on tearing up those agreements - he says they have been wrecked by Mr Arafat.

The prospects now are worse than they were a decade ago. There have also been subsidiary Middle East conferences on specific subjects, like water resources and refugees. But they didn't get very far - it became clear that a political solution had to come first. That is more than ever the case now.

What role might the European Union have in the conference?

Mr Sharon does not like the west European governments. He thinks they are biased against Israel.

President Chirac of France says any regional conference should include the EU, the United Nations and Russia. Together with the United States, these three make up the Quartet, as it is called, which have been trying to co-ordinate action on the Middle East.

So the EU would play a support role, while acknowledging that the Americans have to be the main movers and shakers.

The Arabs know that too, even as they ask the Europeans to get more involved.

Would such a conference have any hope of success?

Not much - though if it could be assembled, that would already imply that the atmosphere had greatly improved.

In fact, times are desperate, and people are casting around for desperate measures.